The Half-Split Method (also known as the Divide-and-Conquer Approach) is generally used by more experienced technicians. The technician will use their experience to make an educated guess as to where the fault may lie, and then progress forward or backward in the particular circuit whether it be.  This approach works for technical, networking or software problems.

The method is a logical way of applying the system knowledge to isolate the fault.  It’s essentially a binary progression.

For example as a technician, you would check the signal at a point in the middle of the system.   Is it good or bad?

If it’s bad, choose a point midway between there and the front of the system; if it’s good, pick a point midway between there and the system output.    Again, is the signal good or bad?

Continue this way, always splitting the remaining section and moving toward the bad area until you find the faulty part.

On a complex system, this method saves troubleshooting time by allowing you to eliminate half of the remaining system with each test.  What could have taken an hour in a sequential search has taken 10 minutes or less.

Good documentation is also required.  While a fault chart or troubleshooting tree are handy, the best documentation will also include an explanation of system operation and the interaction of the sub components.  Good documentation and overall experience can substitute for equipment knowledge, but only just.

Even an experienced technician without documentation wouldn’t have the first idea how to find a problem in an unfamiliar system except to trace the signal through point-by-point.

An example would be the system below.  It depects a computer system with a number of distinct blocks.  One way to fault find this would be to start at Block A and continue checking each block until the fault is found, this would be the linear approach.  However a more efficient way to test this system would be to start testing between block C and D. If this works, then go forward to testing between E and F.  If not, then go back to testing between blocks A and B.

This depicts a small simple system, however in large systems the half split method can significantly save time.

Next: Test Strategies